1/* Copyright (C) 1993-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>.
17
18 As a special exception, if you link the code in this file with
19 files compiled with a GNU compiler to produce an executable,
20 that does not cause the resulting executable to be covered by
21 the GNU Lesser General Public License. This exception does not
22 however invalidate any other reasons why the executable file
23 might be covered by the GNU Lesser General Public License.
24 This exception applies to code released by its copyright holders
25 in files containing the exception. */
26
27#include <libioP.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <shlib-compat.h>
31
32static ssize_t
33_IO_cookie_read (FILE *fp, void *buf, ssize_t size)
34{
35 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
36 cookie_read_function_t *read_cb = cfile->__io_functions.read;
37#ifdef PTR_DEMANGLE
38 PTR_DEMANGLE (read_cb);
39#endif
40
41 if (read_cb == NULL)
42 return -1;
43
44 return read_cb (cfile->__cookie, buf, size);
45}
46
47static ssize_t
48_IO_cookie_write (FILE *fp, const void *buf, ssize_t size)
49{
50 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
51 cookie_write_function_t *write_cb = cfile->__io_functions.write;
52#ifdef PTR_DEMANGLE
53 PTR_DEMANGLE (write_cb);
54#endif
55
56 if (write_cb == NULL)
57 {
58 fp->_flags |= _IO_ERR_SEEN;
59 return 0;
60 }
61
62 ssize_t n = write_cb (cfile->__cookie, buf, size);
63 if (n < size)
64 fp->_flags |= _IO_ERR_SEEN;
65
66 return n;
67}
68
69static off64_t
70_IO_cookie_seek (FILE *fp, off64_t offset, int dir)
71{
72 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
73 cookie_seek_function_t *seek_cb = cfile->__io_functions.seek;
74#ifdef PTR_DEMANGLE
75 PTR_DEMANGLE (seek_cb);
76#endif
77
78 return ((seek_cb == NULL
79 || (seek_cb (cfile->__cookie, &offset, dir)
80 == -1)
81 || offset == (off64_t) -1)
82 ? _IO_pos_BAD : offset);
83}
84
85static int
86_IO_cookie_close (FILE *fp)
87{
88 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
89 cookie_close_function_t *close_cb = cfile->__io_functions.close;
90#ifdef PTR_DEMANGLE
91 PTR_DEMANGLE (close_cb);
92#endif
93
94 if (close_cb == NULL)
95 return 0;
96
97 return close_cb (cfile->__cookie);
98}
99
100
101static off64_t
102_IO_cookie_seekoff (FILE *fp, off64_t offset, int dir, int mode)
103{
104 /* We must force the fileops code to always use seek to determine
105 the position. */
106 fp->_offset = _IO_pos_BAD;
107 return _IO_file_seekoff (fp, offset, dir, mode);
108}
109
110
111static const struct _IO_jump_t _IO_cookie_jumps libio_vtable = {
112 JUMP_INIT_DUMMY,
113 JUMP_INIT(finish, _IO_file_finish),
114 JUMP_INIT(overflow, _IO_file_overflow),
115 JUMP_INIT(underflow, _IO_file_underflow),
116 JUMP_INIT(uflow, _IO_default_uflow),
117 JUMP_INIT(pbackfail, _IO_default_pbackfail),
118 JUMP_INIT(xsputn, _IO_file_xsputn),
119 JUMP_INIT(xsgetn, _IO_default_xsgetn),
120 JUMP_INIT(seekoff, _IO_cookie_seekoff),
121 JUMP_INIT(seekpos, _IO_default_seekpos),
122 JUMP_INIT(setbuf, _IO_file_setbuf),
123 JUMP_INIT(sync, _IO_file_sync),
124 JUMP_INIT(doallocate, _IO_file_doallocate),
125 JUMP_INIT(read, _IO_cookie_read),
126 JUMP_INIT(write, _IO_cookie_write),
127 JUMP_INIT(seek, _IO_cookie_seek),
128 JUMP_INIT(close, _IO_cookie_close),
129 JUMP_INIT(stat, _IO_default_stat),
130 JUMP_INIT(showmanyc, _IO_default_showmanyc),
131 JUMP_INIT(imbue, _IO_default_imbue),
132};
133
134
135/* Copy the callbacks from SOURCE to *TARGET, with pointer
136 mangling. */
137static void
138set_callbacks (cookie_io_functions_t *target,
139 cookie_io_functions_t source)
140{
141#ifdef PTR_MANGLE
142 PTR_MANGLE (source.read);
143 PTR_MANGLE (source.write);
144 PTR_MANGLE (source.seek);
145 PTR_MANGLE (source.close);
146#endif
147 *target = source;
148}
149
150void
151_IO_cookie_init (struct _IO_cookie_file *cfile, int read_write,
152 void *cookie, cookie_io_functions_t io_functions)
153{
154 _IO_init_internal (&cfile->__fp.file, 0);
155 _IO_JUMPS (&cfile->__fp) = &_IO_cookie_jumps;
156
157 cfile->__cookie = cookie;
158 set_callbacks (&cfile->__io_functions, io_functions);
159
160 _IO_new_file_init_internal (&cfile->__fp);
161
162 _IO_mask_flags (&cfile->__fp.file, read_write,
163 _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
164
165 cfile->__fp.file._flags2 |= _IO_FLAGS2_NEED_LOCK;
166
167 /* We use a negative number different from -1 for _fileno to mark that
168 this special stream is not associated with a real file, but still has
169 to be treated as such. */
170 cfile->__fp.file._fileno = -2;
171}
172
173
174FILE *
175_IO_fopencookie (void *cookie, const char *mode,
176 cookie_io_functions_t io_functions)
177{
178 int read_write;
179 struct locked_FILE
180 {
181 struct _IO_cookie_file cfile;
182#ifdef _IO_MTSAFE_IO
183 _IO_lock_t lock;
184#endif
185 } *new_f;
186
187 switch (*mode++)
188 {
189 case 'r':
190 read_write = _IO_NO_WRITES;
191 break;
192 case 'w':
193 read_write = _IO_NO_READS;
194 break;
195 case 'a':
196 read_write = _IO_NO_READS|_IO_IS_APPENDING;
197 break;
198 default:
199 __set_errno (EINVAL);
200 return NULL;
201 }
202 if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
203 read_write &= _IO_IS_APPENDING;
204
205 new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
206 if (new_f == NULL)
207 return NULL;
208#ifdef _IO_MTSAFE_IO
209 new_f->cfile.__fp.file._lock = &new_f->lock;
210#endif
211
212 _IO_cookie_init (&new_f->cfile, read_write, cookie, io_functions);
213
214 return (FILE *) &new_f->cfile.__fp;
215}
216
217versioned_symbol (libc, _IO_fopencookie, fopencookie, GLIBC_2_2);
218
219#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
220
221static off64_t
222attribute_compat_text_section
223_IO_old_cookie_seek (FILE *fp, off64_t offset, int dir)
224{
225 struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
226 int (*seek_cb) (FILE *, off_t, int)
227 = (int (*) (FILE *, off_t, int)) cfile->__io_functions.seek;
228#ifdef PTR_DEMANGLE
229 PTR_DEMANGLE (seek_cb);
230#endif
231
232 if (seek_cb == NULL)
233 return _IO_pos_BAD;
234
235 int ret = seek_cb (cfile->__cookie, offset, dir);
236
237 return (ret == -1) ? _IO_pos_BAD : ret;
238}
239
240static const struct _IO_jump_t _IO_old_cookie_jumps libio_vtable = {
241 JUMP_INIT_DUMMY,
242 JUMP_INIT(finish, _IO_file_finish),
243 JUMP_INIT(overflow, _IO_file_overflow),
244 JUMP_INIT(underflow, _IO_file_underflow),
245 JUMP_INIT(uflow, _IO_default_uflow),
246 JUMP_INIT(pbackfail, _IO_default_pbackfail),
247 JUMP_INIT(xsputn, _IO_file_xsputn),
248 JUMP_INIT(xsgetn, _IO_default_xsgetn),
249 JUMP_INIT(seekoff, _IO_cookie_seekoff),
250 JUMP_INIT(seekpos, _IO_default_seekpos),
251 JUMP_INIT(setbuf, _IO_file_setbuf),
252 JUMP_INIT(sync, _IO_file_sync),
253 JUMP_INIT(doallocate, _IO_file_doallocate),
254 JUMP_INIT(read, _IO_cookie_read),
255 JUMP_INIT(write, _IO_cookie_write),
256 JUMP_INIT(seek, _IO_old_cookie_seek),
257 JUMP_INIT(close, _IO_cookie_close),
258 JUMP_INIT(stat, _IO_default_stat),
259 JUMP_INIT(showmanyc, _IO_default_showmanyc),
260 JUMP_INIT(imbue, _IO_default_imbue),
261};
262
263FILE *
264attribute_compat_text_section
265_IO_old_fopencookie (void *cookie, const char *mode,
266 cookie_io_functions_t io_functions)
267{
268 FILE *ret;
269
270 ret = _IO_fopencookie (cookie, mode, io_functions);
271 if (ret != NULL)
272 _IO_JUMPS_FILE_plus (ret) = &_IO_old_cookie_jumps;
273
274 return ret;
275}
276
277compat_symbol (libc, _IO_old_fopencookie, fopencookie, GLIBC_2_0);
278
279#endif
280